I have a limited understanding of this but I have read both articles. Playing devils advocate, it's easy to say we have a problem and reference where the problems have occurred but its harder to present a solution.
If we do think they need to stop Banks investing our savings deposits, a couple of questions come to mind, how would the Bank realistically have enough capital to then provide loans if it can't use the funds deposited to balance risk?
It could be either they need to stop investing the money being deposited, or banking regulations need to increase the capital that Banks hold outside of their investments.
If they're unable to invest the deposits, how would they provide an interest payment for having your funds if everyone's funds are sitting there not making any money through their investments? If we all deposited our money and they couldn't use it to invest or provide loans with interest, how will they afford to pay back interest on your savings deposits? You would have to forgo those.
My point being, what does the bank get out of holding our savings if they can't do anything with it?
Ultimately I could have a poor understanding and I'm just testing my thoughts.